• Title/Summary/Keyword: elemental components

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Study on the Components of Glehniae Radix (해방풍의 성분연구)

  • Seo, Yoon-Kyo;Ryu, Kyung-Soo
    • Korean Journal of Pharmacognosy
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    • v.7 no.4
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    • pp.233-235
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    • 1976
  • Substances $I{\sim}VII$ are isolated from the root of Glehnia littoralis which has been often used as a subsitute of Bang-Poong in Korea. White needle crystalline substance of $C_{29}H_{50}O$, m.p. $137{\sim}139^{\circ}C$ was confirmed as ${\beta}-sitosterol$ through elemental analysis, derivative synthesis, IR and physicochemical tests. Moreover, it was concluded that white needle crystal of $C_{12}H_{8}O_{4}$, m.p. $188{\sim}189^{\circ}$ was confirmed as bergapten, through a contrast test with standard substance and by UV and IR-spectra. It was found that substance III and VII coincided with the Rf values of imperatorin and umbelliferone and to its colors under the UV-ray, and its similarity to UV-spectrum can be recognized, but their melting points are remarkedly different respectively.

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Chlorine behavior during fluidized bed combustion of RDF (RDF 유동층 연소시 Cl의 거동)

  • Lee, H.M.;Kak, Y.H.;Kim, W.H.
    • 한국연소학회:학술대회논문집
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    • 2001.11a
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    • pp.137-141
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    • 2001
  • The behavior of Cl is important to prevent HCl exhausted by incineration of RDF. Because RDF is composed of municipal wastes, its calorific value is very various. Thus components of RDF are to be analyzed and elemental analyze and calorific value are to be done. And in order to find the behavior of Cl during RDF combustion, Cl included in exhaust gas and ash is captured and analyzed. RDF which made by municipal and $Ca(OH)_2$ with regular ratio(Ca/0.5Cl) is incinerated in fluidized bed combustor. Cl included in exhaust gas and fly ash is captured and analyzed. Finally the change of Cl concentration included in exhaust gas and ash is analyzed and the behavior of Cl is investigated.

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Studies on the Synthesis of (3 - Alkyl benzimidazolium)-TCNQ Complexes (유기전하 이동착체의 합성에 관한 연구)

  • Sohn, Byoung-Chung;Hwang, Kyo-Hyun;Jeong, Soon-Wook
    • Journal of the Korean Applied Science and Technology
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    • v.11 no.1
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    • pp.33-37
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    • 1994
  • In this research, (3-alkyl benzimidazalium)-TCNQ complexes were synthesized to obtain the necessary components for Langmuir-Blodgett Technique. (3- Alkyl benzimidazolium)-TCNQ complexes were prepared by the reaction of LiTCNQ with 3-alkyl benzimidazolium bromides and the products were confirmed by elemental analysis. FT-IR, UV-Visible spectroscopies. FT-IR spectra of (3-alkyl benzimidazolium) TCNQ(1:2) complexes were characterized by a broad band with a maximum at about $2900cm^{-1}$ appears and were ascribed to electronic rather than vibrational absorption.

A Comparison of $PM_{2.5}$ Elemental Components Measured at Industrial and Urban Sites during Spring Season (봄철황사기간중 공단 및 도심지역에서 측정한 $PM_{2.5}$ 분진의 원소성분 비교연구)

  • 박승식;류성윤;김영준;이재훈
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.327-328
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    • 2001
  • 한반도 지역은 중국과 인접해 있는 관계로 매년 봄철이면 고비사막이나 중국의 황토고원에서 발생한 황사(yellow sand) 현상에 의해 많은 고통을 겪고 있다. 중국본토에서 발생된 황사에어로졸은 수 천 km를 장거리 이동하여 한국 및 일본등의 대기에어로졸의 질량 loading에 엄청난 변화를 초래할 뿐 만 아니라, 에어로졸을 구성하고 있는 화학적 조성에도 많은 변화를 가져온다. 특히, 에어로졸 중에서도 입자 크기가 2.5-10 $\mu\textrm{m}$사이에 있는 조대입자 ("coarse mode")의 광학적 및 화학적 특성에 많은 변화를 야기시키는 것으로 알려져 있다. (중략)

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A Comparison of $PM_{2.5}$ Elemental Components Measured at Gosan, Jeju and Gwangju Urban Site (제주 고산 및 광주 도심지역에서 측정한 $PM_{2.5}$ 분진의 원소성분 비교연구)

  • 김영준;류성윤;김정은;박승식;한진석;홍유덕;정다위;문광주
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.87-88
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    • 2002
  • 동북아 지역은 중국과 인접해 있는 관계로 매년 봄철이면 고비사막이나 중국의 황토고원에서 발생한 황사(yellow sand) 현상에 의해 많은 고통을 겪고 있다. 중국본토에서 발생된 황사에어로졸은 수 천 km 장거리 이동하여 한국 및 일본 둥의 대기에어로졸의 질량 loading에 엄청난 변화를 초래할 뿐 만 아니라, 에어로졸을 구성하고 있는 화학적 조성에도 많은 변화를 가져온다. 일반적으로 분진은 입경에 따라 미세입자와 거대입자로 나눌 수 있다. (중략)

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The Wear Mechanism of Carbon(WC/C) Thin Film in Lubricated Contact (WC/C 박막의 윤활접촉하의 마멸기구)

  • Ahn, Hyo-Sok;Kim, Doo-In
    • Tribology and Lubricants
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    • v.24 no.6
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    • pp.302-307
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    • 2008
  • The running-in behaviour of the metal carbon coating (WC/C) was evaluated with regard to its applicability as wear-resistant coating for key components in engines. Reciprocating wear tests under lubricated condition employing an oscillating friction wear tester were performed to investigate the tribological behaviors of the coatings in ambient environment. Confocal microscopy and scanning electron microscopy were used to observe worn surfaces and the wear scars on the steel balls. Elemental composition of the coating and worn surfaces were characterized using Auger electron spectroscopy. The friction behavior of WC/C coating was comparable to common carbon-based coatings. Thin tribofilm was formed on the worn surface of the steel ball due to material transfer and tribochemical reaction whereas there was no evidence of tribofilm generation on the coating surface. indicating the chemical innertness of WC/C coating.

Parameterising a Microplankton Model

  • Lee, Jae-Young;Tett, Paul;Kim, Kyung-Ryeul
    • Journal of the korean society of oceanography
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    • v.38 no.4
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    • pp.185-210
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    • 2003
  • This paper describes and assesses the parameterisation of MP, the microplankton compartment of the carbon­nitrogen microplankton­detritus model. The compartment is 'the microbial loop in a box' and includes pelagic bacteria and protozoa as well as phytoplankton. The paper presents equations and parameter values for the autotroph and microheterotroph components of the microplankton. Equations and parameter values for the microplankton as a whole are derived on the assumption of a constant 'heterotroph fraction'. The autotroph equations of MP allow variation in the ratios of nutrient elements to carbon, and are largely those of the 'cell­quota, threshold­limitation' algal growth model, which can deal with potential control of growth by several nutrients and light. The heterotroph equations, in contrast, assume a constant elemental composition. Nitrogen is used as the limiting nutrient in most of the model description, and is special in that MP links chlorophyll concentration to the autotroph nitrogen quota.

A Study on the Process Design of Non-Axisymmetric Forging Components (비축대칭 형상의 단조 공정 설계에 관한 연구)

  • Kim, Y.H.;Bae, W.B.;Park, J.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.10
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    • pp.57-68
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    • 1995
  • An upper bound elemental technique (UBET) program has been developed to predict forging load, die-cavity filling, preform in non-axisymmetric forging. To analyze the process easily, it is suggested that the deformation is divided into two different parts. Those are axisymmetric part in corner, plane-strain part in lateral. The plane-strain and axisymmetric parts are combined by building block method. And the total energy is computed through combination of three deformation parts. A dumbbell-type preform has been obtained from height and volumetric compensations of the billet based on the backward simulation. Experimetns have been carried out with pure plasticine at room temperature. Theoretical predictions are in good agreement with expereimental results.

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Studies on the Components of Evodia daniellii $H_{EMSLEY}$ in Korea (한국산 오수유성분에 관한 연구)

  • Chung, Bo-Sup
    • Korean Journal of Pharmacognosy
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    • v.1 no.4
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    • pp.119-124
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    • 1970
  • Evodia daniellii $H_{EMSLEY}$, a plant belonging to Rutaceae, is cultivated in Korea and used as a folkmedicine for gastric inflammation, extermination of noxious insects, and headache. The seed oil of this plant also has been used in various diseases, for example, dermatitis, scabies and so forth. From the barks, fruit peels, and seed oil of Evodia daniellii $H_{EMSLEY}$, four crystalline compounds were isolated. Three compounds except one were characterized as methyl sinapate, bergapten, and evodiamine by m.p. determination, elemental analysis, UV, IR, NMR spectra and mass analysis. Even though methyl sinapate was a known synthetic compound, it was not yet reported as a natural product. From the seed oil, unsaponifiable fraction was separated and was analyzed. It was considered to be consisted with sterols, hydrocarbons and tocopherols.

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Determination of the Degree of Alloying by Detection of Residual Ferromagnetic Elements for Intermetallic Alloys Processed by Mechanical Alloying (잔류 자성원소 검출에 의한 금속간화합물의 기계적 합금화 공정에서의 합금화 정도 해석)

  • Ur, Soon-Chul
    • Korean Journal of Materials Research
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    • v.13 no.9
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    • pp.561-566
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    • 2003
  • Mechanical alloying(MA) process using elemental powders followed by hot pressing has been applied to some intermetallic alloy system containing ferromagnetic elements, such as NiAl and $FeSi_2$. A modified thermogravimetric analysis (TGA) technique was used to investigate the degree of alloying in milled powders and hot consolidated specimens as well as heat-treated bulk specimens. It is shown that the measurement of Curie temperatures in MA intermetallic powders and consolidated specimens containing ferromagnetic components, when determined as a function of milling and heat treatment parameters, can give some insight into the progress and mechanism of alloying.